1. Field of the Invention
The present invention relates to a substrate treatment method and a substrate treatment apparatus for treating a substrate such as a semiconductor wafer.
2. Description of the Related Art
In semiconductor device production processes, a treatment liquid is supplied to a front surface of a substrate such as a semiconductor wafer to treat the front surface of the substrate with the treatment liquid.
A substrate treatment apparatus of a single substrate treatment type adapted to treat a single substrate at a time, for example, includes a spin chuck which generally horizontally holds the substrate and rotates the substrate, and a nozzle which supplies the treatment liquid to the front surface of the substrate rotated by the spin chuck. For example, a chemical liquid is supplied to the substrate held by the spin chuck, and then a rinse liquid is supplied to the substrate, whereby the chemical liquid is replaced with the rinse liquid on the substrate. Thereafter, a spin drying step is performed to remove the rinse liquid from the substrate. In the spin drying step, the substrate is rotated at a higher speed to spin off the rinse liquid from the substrate (to dry the substrate). In the spin drying step, it is impossible to completely remove the rinse liquid trapped in gaps of a minute pattern formed on the front surface of the substrate, resulting in insufficient drying.
To cope with this, U.S. Pat. No. 5,882,433 proposes a method such that an organic solvent such as liquid isopropyl alcohol (IPA) at an ordinary temperature is supplied to the front surface of the substrate after the rinsing step, whereby the rinse liquid trapped in the gaps of the pattern on the front surface of the substrate is replaced with the organic solvent for drying the front surface of the substrate.